Many specialist herbivores eat foods that are apparently low quality. The compensatory benefits of a poor diet may include protection from natural enemies. Several bee lineages specialize on pollen of the plant family Asteraceae, which is known to be a poor-quality food. Here we tested the hypothesi

An outstanding goal in speciation research is to trace the mode and tempo of the evolution of barriers to gene flow. Such research benefits from studying incipient speciation, in which speciation between populations has not yet occurred, but where multiple potential mechanisms of reproductive isolat

Early Proterozoic supracrustal rocks near Gunnison and Salida, Colorado include tholeiitic basalt, dacite to rhyolite, and intercalated sedimentary rocks. These were intruded by essentially synchronous gabbroic sheets, folded, and intruded by major plutons ranging from quartz diorite to granite. Pre

Patterns of substrate size preference of predatory stoneflies were measured in a western Colorado, USA, stream and associations were examined between substrates and other physical and biological variables. Predatory Megarcys signata (Perlodidae) were found disproportionately on large stones that wer

Values increased with increasing size of the predator, and inclusion of the C/A term indicated that predators would obtain greater reward from small relative to large prey, and from dipterans relative to mayflies.

Journal Article The Annual Cycle and Fat Storage in Two Populations of Golden-Mantled Ground Squirrels Get access Barbara Hibbs Blake Barbara Hibbs Blake Department of Biology, Yale University, New Haven, Connecticut Search for other works by this author on: Oxford Academic Google Scholar Journal of

AbstractQuestionsIs it possible to predict the composition of local plant assemblages? Trait‐based approaches have offered some promise, especially in cases where deterministic processes such as environmental filtering and niche differentiation shape communities. In this study, we asked how much int

The bottom-up effects of plant food quality and quantity can affect the growth, survival, and reproduction of herbivores. The larvae of solitary bee pollinators, consumers of nectar and pollen, are also herbivores. Although pollen quantity and quality are known to be important for larval growth, lit

The timing of life events (phenology) can be influenced by climate. Studies from around the world tell us that climate cues and species' responses can vary greatly. If variation in climate effects on phenology is strong within a single ecosystem, climate change could lead to ecological disruption, b

Behavioral experiments were carried out in flow-through observation boxes in New York and Colorado streams to determine whether interactions between pairs of predaceous stoneflies were characterized by exploitative or interference competition and to determine the effect of prey density on such inter

Heritable genetic variation is necessary for populations to evolve in response to anthropogenic climate change. However, antagonistic genetic correlations among traits may constrain the rate of adaptation, even if substantial genetic variation exists. We examine potential genetic responses to select

AbstractThe hyporheic zone, where surface water and groundwater mix, is an important microbial habitat where biogeochemical reactions influence water quality. We show that spatial variability in hyporheic flow in the East River near Crested Butte, CO, drives heterogeneity in streambed geochemical co

Abstract One cause of reproductive isolation is gamete competition, in which conspecific pollen has an advantage over heterospecific pollen in siring seeds, thereby decreasing the formation of F1 hybrids. Analogous pollen interactions between hybrid pollen and conspecific pollen can contribute to po

Climatic shifts to warmer and often drier conditions are challenging terrestrial species worldwide. These shifts are occurring more rapidly at higher elevations and latitudes, likely causing disproportionate effects to mammalian hibernators there. While there is some information about how these spec

Miocene-Pliocene history is recorded in south-central Colorado by sediments deposited in subsiding basins bounded by fault-block mountains and by faulted sedimentary and volcanic deposits lying on a channeled late Eocene erosion surface of regional extent. The San Luis Valley and upper Arkansas Vall

It is stressed that chemotactile cues are involved only in the final step of oviposition, and that understanding foodplant choice in nature will require in-depth investigation into the mechanics of individual search processes.

Organisms must often make developmental decisions without complete information about future conditions. This uncertainty-for example, about the duration of conditions favorable for growth-can favor bet-hedging strategies. Here, we investigated the causes of life cycle variation in Osmia iridis, a be

AbstractUnderstanding the partitioning of snow and rain contributing to either catchment streamflow or evapotranspiration (ET) is of critical relevance for water management in response to climate change. To investigate this partitioning, we use endmember splitting and mixing analyses based on stable